i m bret baier in washington. big story here late changes to the republican national convention as the g.o.p. ticket barnstorms their way to tampa. tonight on special report, news that mitt romney s wife ann will get a prime time speaking slot. her speech is moving. we ll explain why that happened and why it s important. along with economic attacks, mitt romney today made a joke about the controversy over president obama s birth certificate. that drew a quick and pointed response from the obama campaign. tropical storm isaac could be uninvited guest in tam pennsylvania ge ate live up tampa and we get a live update on where it might be headed and what might happen if it heads into a hurricane to head tampa s way. new study states household income has fallen more since the economic recovery began than in the throes of the